This invention is directed to a system and method for selectively converting electromagnetic waves (signals) from circular to linear polarization or vice versa.
The invention herein is particularly useful in converting commercial satellite communications transmitted as circular polarized signals to linearly polarized signals so that home TV receivers may conveniently receive such signals. With the polarization converter of this invention it is also possible to receive linearly polarized signals if desired.
The present system may be remotely operated by the home owner (operator) to switch between different polarized transmissions from different or the same satellites, for example, from a satellite in the U.S.A. eastern time zone transmitting left hand circularly polarized microwave TV signals to a satellite in the U.S.A. central time zone transmitting right hand circularly polarized microwave TV signals. The system is not only inexpensive but also it provides polarization conversion with only about 1/10 of a db losses at the primary frequencies of interest, 10,000 GHz to 15,000 GHz, but also unexpectedly provides reception separation between left hand and right hand circularly polarized signals of at least about 15 to 20 db received by the converter at the same frequency.
It is to be understood that the system of the invention will operate over a broad range of microwave frequencies.
The converter may also be used for transmitting both circular or linear polarized signals.